Abstract

1. Sodium phenanthrene-9-carboxylic acid produced in normal cats, rabbits and mice an effect suggesting a veratrine-like action on skeletal muscle.

2. In cats and rabbits after administration of the compound, isotonic and isometric gastrocnemius muscle contraction records were often double or multiple peaked and usually showed a prolonged relaxation phase of from 1 to 6 seconds in duration. An increase in the amplitude of contraction was also commonly observed.

3. Characteristic records were obtained on direct and indirect stimulation with the sciatic nerve cut, indicating a peripheral site of action, and on direct stimulation in the curarized animal, localizing the point of action to the muscle.

4. This peculiar muscular effect was also produced, although to a lesser degree, by four other 9-substitution products of phenanthrene but not by the 2- and 3-substituted carboxylic acids.

5. Sodium phenanthrene-9-carboxylic acid did not produce this phenomenon in frogs but instead elicited a morphine-like picture.